Version 2.1.1: G command for smart going

The big fix for 2.1.1 is the G command. The commit is here, for people interested in code. So what does the G command do?

It nudges you on a very good way to go next. It's a super-powered version of O (shortcut for OUT,) and in fact it re-uses a lot of O's code, but it looks a bit further if there is more than one exit.

Other stuff? Well, testing the code for G pointed me to other code I wanted to tweak. Oh, and stuff I wanted to add. There wasn't much. But when you play through several times, small things appear. They felt worth fixing.

--graphics are now more reliably updated on point-scoring commands. This usually only failed if the player had typed several commands first.

--one more new set of books in the bookshelf (this seems to be fun to add each sub-release. I also added # START RANDOM BOOKS to search for in the source.)

--internal code: renamed points_left and points_right to west and east and also created dynamic_integers to track hub scores